Function fitCallbacks

tfjs-vis/src/show/history.ts:254–307

(
    container: Drawable, metrics: string[],
    opts: FitCallbackOptions = {})

 * 'show'}
 */
export function fitCallbacks(
    container: Drawable, metrics: string[],
    opts: FitCallbackOptions = {}): FitCallbackHandlers {
  const accumulators: FitCallbackLogs = {};
  const callbackNames = opts.callbacks || ['onEpochEnd', 'onBatchEnd'];
  const drawArea = getDrawArea(container);

  const historyOpts = Object.assign({}, opts);
  delete historyOpts.callbacks;
  function makeCallbackFor(callbackName: string) {
    return async (_: number, log: Logs) => {
      // Set a nicer x axis name where possible
      if ((/batch/i).test(callbackName)) {
        historyOpts.xLabel = 'Batch';
      } else if ((/epoch/i).test(callbackName)) {
        historyOpts.xLabel = 'Epoch';
      }

      // Because of how the _ (iteration) numbers are given in the layers api
      // we have to store each metric for each callback in different arrays else
      // we cannot get accurate 'global' batch numbers for onBatchEnd.

      // However at render time we want to be able to combine metrics for a
      // given callback. So here we make a nested list of metrics, the first
      // level are arrays for each callback, the second level contains arrays
      // (of logs) for each metric within that callback.

      const metricLogs: Logs[][] = [];
      const presentMetrics: string[] = [];
      for (const metric of metrics) {
        // not all logs have all kinds of metrics.
        if (log[metric] != null) {
          presentMetrics.push(metric);

          const accumulator =
              getAccumulator(accumulators, callbackName, metric);
          accumulator.push({[metric]: log[metric]});
          metricLogs.push(accumulator);
        }
      }

      const subContainer =
          subSurface(drawArea, callbackName, {title: callbackName});
      history(subContainer, metricLogs, presentMetrics, historyOpts);
      await nextFrame();
    };
  }

  const callbacks: FitCallbackHandlers = {};
  callbackNames.forEach((name: string) => {
    callbacks[name] = makeCallbackFor(name);
  });
  return callbacks;
}

interface FitCallbackHandlers {
  [key: string]: (iteration: number, log: Logs) => Promise<void>;